Another reason to paint KRs light colors is bubbles forming in the skin. At high temperatures the urethane foam offgases and creates bubbles under the skin which delaminates the skin from the foam, and then expands it into a bubble. When the plane cools off, the bubble remains. You'd be amazed at the difference in surface temperature of a plane painted white compared to a darker color like red or black. It's easily in the order of 70 degrees (that's from personal observation, but there's a chart in the KR builder manual for various colors, as well as online).
The KR structure is wood, so it doesn't have a lot to do with structural issues.. but you could count delaminating skin as a potential structural problem, I suppose. But it's not like the wings are going to sag or anything. It's probably a good idea to let your plane cure in the sun and get the bubble making over with before the wings are painted, but I did that and still get bubbles. I'm guessing the only sure-fire cure is to use a different kind of foam. Right now I proably have 15 different bubbles to deal with, from an inch square to one 4"x12" on the wing. Speaking of such things, has anybody painted the top of the plane metallic silver and noticed degradation of radio signals from an internal com antenna? I'd still like to paint the top of my plane silver, but our antenna expert warns that the aluminum metallic flakes will have a serious impact. I figure a test is in order, but if somebody else has already done a before/after comparison, that'd be helpful. Mark Langford ML at N56ML.com website at http://www.N56ML.com --------------------------------------------------------
